Methods and apparatuses for processing hydrocarbons to produce light olefins

A method for processing hydrocarbons to produce light olefins, the method comprising:

• passing a hydrocarbon feed stream into a feed inlet of a reactor, wherein the reactor comprises:
• an upper reactor portion defining an upper reaction zone, the upper reactor portion comprising a catalyst inlet and a hydrocarbon product outlet, wherein the catalyst inlet and the hydrocarbon product outlet are positioned at or near the top of the upper reactor portion;
• and
• a lower reactor portion defining a lower reaction zone, the lower reactor portion comprising a feed inlet and a catalyst outlet, wherein feed inlet and the catalyst outlet are positioned at or near the bottom of the lower reactor portion, and wherein the lower reaction zone is in fluid communication with and adjacent to the upper reaction zone;
• and
• wherein:
• the catalyst has a downward superficial velocity through the upper reactor portion and the lower reactor portion and the hydrocarbon feed stream has an upward superficial velocity through the upper reactor portion and lower reactor portion such that the hydrocarbon feed stream and the catalyst move with a counter-current orientation;
• the upper reaction zone operates with a counter-current plug flow regime, wherein the catalyst-to-oil ratio in the upper reaction zone is from 5 to 100 and the superficial velocity of the hydrocarbon feed stream in the upper reaction zone is 3.0 m/s or less;
• the lower reaction zone operates with a dense bed fluidization regime, wherein a weight hourly space velocity of the lower reaction zone is from 1 to 200 hr−1;
• and
• contacting the catalyst with the hydrocarbon feed stream cracks one or more components of the hydrocarbon feed stream and forms a hydrocarbon product stream, wherein the hydrocarbon product stream comprises one or more of ethylene, propylene, or butene;
• and
• passing the hydrocarbon product stream out of the upper reaction zone through the hydrocarbon product outlet.